Redesign web session clustering ------------------------------- Key: WFLY-406 URL: https://issues.jboss.org/browse/WFLY-406 Project: WildFly Issue Type: Task Components: Clustering Reporter: Paul Ferraro Assignee: Paul Ferraro Fix For: 8.0.0.Alpha1 The current web session replication code has been around for ages and suffers from a number of issues: * By maintaining a separate local map of sessions in conjunction with the session data stored in the distributed cache, stale data is inevitable - an number of issues have cropped up in EAP testing. * Extra concurrency measures are required to ensure synchronicity of the local session map with the distributed cache. * Extra logic/locking is required to invalidate the local session map is required per request * AtomicMaps, on which the currently implementation relies, have proven buggy * Session access outside of the scope of the replication valve is possible and problematic * Maintaining sessions locally means that the clustering code needs to implement passivation and expiration manually - instead of leveraging Infinispan full capabilities. * The current code base is tightly coupled to JBoss Web. Migrating the code to support Undertow will inevitably introduce issues and code duplication. The new design will incorporate a proper SPI for the servlet container. Thus the logic to integrate with Undertow vs JBoss Web will be relatively thin.